The present application claims priority under 35 U.S.C. xc2xa7 119 of Swiss Patent Application No. CH 2000 0499/00, filed on Mar. 16, 2000, the disclosure of which is expressly incorporated by reference herein in its entirety.
1. Field of the Invention
The present invention relates to an apparatus for sterilization or treatment, using ionophoresis, of the canals of a tooth infected by pathogens. The present invention relates to a method for sterilization or treatment, using ionophoresis, of the canals of a tooth infected by pathogens.
2. Discussion of Background Information
The principle of treating an infected tooth using ionophoresis is known. See P. D. Bernard, xe2x80x9cRapid and Radical Treatment of the Pulpa Tissues and Periapical Affections Using the New Methods of lonophoresis and of Dia-dynamic Therapyxe2x80x9d (ll trattamento rapido e radicale delle gengive pulpari e delle affezioni periapicali mediante l nuovi metodi di ionoforesi e die terapia diadi-namica), which was published and edited by the Physiotechnie SA (Company), Paris, (1929), and Ph. Lagarde and R. P. Lagarde, xe2x80x9cTreatment of Infected Teethxe2x80x9d (Trattamento dei denti infetti), a study published sometime after 1974 in France by the Imprimeriex Company, 51bis Av. de Pessicart, Nice. The Lagarde study cites a large bibliography concerning various methods of treating dental infections among which is included a method for using ionophoresis. These publications illustrate devices or apparatuses, which are useful for ionophore treatment; however, the publications do not describe the present inventive apparatus or method. Rather, the publications give some general indications which do not provide anything other than a general knowledge concerning the formation of xe2x80x9cOHxe2x80x9d ions penetrating the xe2x80x9caberrantxe2x80x9d canals of the teeth.
French patent 916843 describes an apparatus and method useful in medical or dentistry electrotherapy comprising supplying direct current to a circuit, the output current of the circuit being regulated by two potentiometers. The direct current is superimposed with a source of low voltage alternating current, the voltage of which can be regulated by another potentiometer which is pre-set not as a function of the voltage it supplies but rather is set in such a manner for obtaining an optimum analgetic effect with respect to the intensity of the direct current supplied. In other words, an alternating current is applied to the direct current such that the alternating current is superimposed as a low frequency sine differential with a potential of 5 volts, thus providing an anaesthetic action when it is superimposed to an externally supplied direct current of 1 milliamp. However, if this same 5 volt ac voltage is applied to a direct current of 3 or 4 milliamps, its action upon the sensitivity predominates, and becomes intolerable with a direct current intensity of 5 milliamps.
FR 916843 teaches a method for electro-therapeutic dentistry treatment where an anaesthetic effect is obtained. This anesthetic effect is different from the present invention which is directed to a method of sterilization (and thus of disinfection) of the canals of the tooth treated using ionophoresis. Furthermore, FR 916843 also states that in some cases the direct current is tolerated badly, when an alternating current is superimposed thereon. Thus, FR 916843 does not teach the use of ionophoresis as a therapeutic method for treating a tooth infected with a pathogen and does not teach an apparatus suitable for implementing the inventive therapeutic method.
CH-257243 teaches an electrotherapeutic apparatus for permitting the generation of a modulated current of a frequency of a plurality of seconds as desired and a syncope current of short periods, the apparatus being useful for the treatment of pain, for the treatment of atonicity and for the diagnosis of neuro-muscular disorders by applying a modulated current, which is generated by thermoionic valves co-operating with interrupt relays. On the other hand, the apparatus of the present invention is structurally different from the apparatus of CH-257243 and the method of the present invention is used for a different utility, treating a tooth infected by a pathogen. It should be noted that an apparatus described in the Ph. And R. P. Lagarde study, page 29, uses two poles, namely, a negative electrode and a positive electrode. The negative electrode is a metallic probe which is shaped as a needle so as to penetrate into the depth of a canal of the tooth to be treated, whereas the positive electrode is brought into direct contact with a body zone of the patient and preferably shaped as a metallic cylinder which the patient holds in his hand.
The use of an alternating current in other apparatus, as well as other electrophoretic methods, predominantly generates an anaesthetizing effect rather than a sterilizing effect. To obtain an anaesthetizing effect, it is necessary to make sure that after a positive current impulse a negative impulse follows, as the anaesthetizing effect is based on the decoding of the nerve ends. This mechanism of anaesthesia does not yield satisfactory results. For this reason, the anaesthetizing effect of the ionophoretic treatment is not used today.
The present invention relates to an apparatus for treating a tooth infected by a pathogen and to a method for treating a tooth infected by a pathogen. The present invention provides for the application of a direct current rather than an alternating current, which is different from other practice and teachings. To obtain the desired treatment, e.g., a disinfection effect or sterilization, it is sufficient to apply a direct current which advantageously can be metered easily in its timing. Furthermore, a direct current can be applied at lower voltage and over shorter time periods than an alternating current, thereby resulting in a reduction of the dangers and of the total application time.
The present invention provides an apparatus for sterilizing a tooth using ionophoresis and provides optimum characteristics for obtaining the sterilizing effect within the shortest possible time and eliminates the disadvantages of other devices. In other apparatus, it has been found that the applied electric current is varied and that there are variations in the circuit impedance Z. The variation in the impedance in a circuit in which one of the poles directly contacts the skin of the patient has many causes, the main one being the variation in humidity of the skin tissue caused by sweating.
The variations in the impedance of the circuit are likely caused by physiologic effects, which are uncontrollable and are foreseeable by the operator. These variations greatly impair the constancy of the current applied, thus rendering control of the working method difficult and endangering the good result of the treatment. The present invention obviates the aforementioned problems and thus enables treatment of a patient despite the local physiologic conditions of the patient.
In accordance with an embodiment of the present invention, the apparatus applies an electric current as a direct current and the direct current is generated by an adjustable generator which normally supplies the current at a maximum voltage of about 89 volts. The apparatus also has an electric circuit which maintains the direct current constant as the impedance Z of the circuit varies by taking into account the fact that impedance Z essentially is determined by the skin tissue of the body zone of the patient, normally a hand, through which the current passes.
The apparatus and method of the present invention have advantages over other apparatus and methods, namely, the speed of the treatment, the reduction of risks owing to the reduced voltage of the applied current and the ability to control the treatment free from the influence of uncontrollable parameters, such as sweat secretion of the patient, the degree of humidity of the air in the surrounding room, etc.
In another preferred embodiment of the present invention, the apparatus may comprise a programmable microprocessor, which monitors and controls all functions of the apparatus.
The present invention relates to an apparatus for treating a tooth infected by a pathogen comprising: at least one adjustable electric voltage generator for generating direct current; an applicator device having a first pole and a second pole, the first pole being formed as a needle so as to penetrate into a canal of the infected tooth and the second pole being brought into direct contact with a zone of a body of a patient having the infected tooth; and an electric circuit for maintaining the direct current constant while an impedance of the at least one adjustable electric voltage generator varies, the impedance being determined by the zone of the body of the patient where the direct current passes.
In the apparatus, the direct current has a voltage of not more than about 89 volts and the apparatus may also comprise a second electric circuit for limiting an amperage of the direct current below about 5 mA.
The apparatus can further comprise a timer for pre-setting a time duration of an application of the direct current to the patient being treated. The apparatus can further comprise a control device for controlling the amperage of the direct current, the control device and the timer being capable of manual operation.
In another embodiment, the apparatus can further comprise a programmable microprocessor for monitoring and controlling all functions of the apparatus. The programmable microprocessor can have a safety arrangement which permits the start of an ionophoresis treatment after an operator has confirmed that the tooth to be treated has been subject to a satisfactory anaesthesia by the operator effecting a suitable pain test. The safety arrangement can comprise an electric test discharge emitter circuit.
The present invention also relates to a method for treating a tooth infected by a pathogen comprising: applying direct current into a canal of the infected tooth and maintaining the direct current constant during a duration of an application of the direct current to the infected tooth. The direct current can have a current voltage of not more than about 89 volts and an amperage of the direct current below about 5 mA.
In the method, the duration of an application of the direct current to the patient being treated is dependent upon the amperage of the direct current, a time of application of the direct current, a position in the dental arc of the tooth being treated and a pathology of the tooth. The duration of an application of the direct current to the patient being treated can be determined by taking into consideration the product of the amperage of the direct current and the time of application of the direct current.
In the method, the amperage of the direct current is controlled by an operator.
In another embodiment of the method, a programmable microprocessor can be used which monitors and controls the amperage of the direct current and the time duration of the application of the direct current.
In the method, the treatment is started after an operator has confirmed that the tooth to be treated has been subject to a satisfactory anaesthesia by the operator effecting a suitable pain test.
In the method, the quantity of direct current applied to the infected tooth can range from about 100 to about 1000 mAsec, and preferably from about 200 to about 500 mAsec.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.